The present invention relates to discharge chute systems for concrete hauling vehicles and, more particularly, to a dual discharge chute system including an adjustable high discharge stub chute.
Various types of vehicles used to haul concrete to a construction site and to discharge the concrete at a selected location are well known in the art. In a conventional truck mixer, a rotatable frustoconical drum with spiral mixing and discharge blades is charged with the ingredients for a batch of concrete or with premixed concrete and travels to the job site with further mixing occurring during transit. At the construction site, reversal of drum rotation causes the concrete to be discharged, most often rearwardly through a small discharge opening in the rear of the drum. A discharge chute is positioned beneath the discharge opening to direct concrete being discharged from the drum to a placement site by swinging the chute laterally about a vertical pivot and/or moving the opposite end of the chute up or down. The vertical position of the discharge opening is limited in height and, because concrete directed onto the discharge chute must slide or flow along it by gravity, there is generally a severe limitation on the effective placement height of the discharge end of the chute. Another problem inherent in the use of truck mixers is the relatively slow discharge capacity because of its dependence on drum rotation alone to effect discharge.
Another type of concrete delivery vehicle utilizes an open top concrete haul body, either with or without mechanical agitation for the concrete, which haul body can be tilted upwardly to discharge the concrete through a rear discharge opening. The haul body is provided with a rearwardly and upwardly tapering construction such that the rear discharge opening is supported in an inherently elevated position. The haul body tilt axis is located immediately below the discharge opening and, by tilting the haul body upwardly, rapid discharge of the concrete may be attained. A discharge chute somewhat like that used in a truck mixer may be used to distribute the concrete dumped from the haul body in a more or less conventional manner. However, the conventional discharge chute is typically made to be removed or mounted to swing away from the rear of the vehicle to a stored position when not in use. Although height restrictions with this apparatus are somewhat less of a problem, the conventional discharge chute nevertheless exhibits some of the same problems posed by the discharge chute of a conventional truck mixer.
An advantage of a tilting haul body vehicle is that it may be backed directly against a concrete receiving device, such as a stationary or movable hopper with a high upper opening edge, and the concrete discharged by dumping directly over the upper edge of the hopper. To facilitate this direct high discharge, it is known to temporarily fasten a fixed position chute to the supporting frame immediately below the discharge opening to bridge the relatively short span between the discharge opening in the haul body and the edge of the hopper. However, such a demountable, fixed position stub chute precludes alternate use of the conventional swing-away chute and, therefore, must be manually detached and stored after use. Because crane-operated and other types of concrete hoppers at job sites may be regularly moved from one location to another, it is often desirable to selectively utilize either the conventional swing-away discharge chute or the short stub chute depending on the location and positioned height of the receiving hopper. It would be most desirable, therefore, to have a high discharge stub chute which could be utilized with a conventional swing-away chute assembly and which was not burdened with the problem of tedious manual mounting and demounting, so that conversion use of from one chute to the other would be easily facilitated.